氮肥水平对强筋小麦产量和氮素利用的影响

Nitrogen Fertilizer Level:Effects on Yield and Nitrogen Utilization of Strong Gluten Wheat

为明确强筋小麦产量与效率相协同的最优施氮量,试验选用‘济麦20’和‘洲元9369’2个优质强筋小麦品种为试验材料,设置0、120、180、240、300 kg N/hm^2等5个施氮水平,用烘干法和凯氏定氮法分别测定小麦成熟期干物质量积累和含氮量,用以计算小麦氮素积累及氮素利用相关指标。结果表明,随氮肥投入量的增加,小麦产量呈现先升高后降低的变化趋势,其中‘济麦20’在N180和N240下达最高产量7.28 t/hm^2和7.26 t/hm^2,其较高的产量主要源于相对平衡的产量构成因素以及较高的干物质积累量(平均18.54 t/hm^2);‘洲元9369’在N180下产量最高达7.75 t/hm^2,其较高的产量主要源于较高的单位面积穗数(970.65万/hm^2)、穗粒数(30.83粒)、较高的干物质积累量(20.77 t/hm^2)和收获指数(37.33%)。虽然氮肥偏生产力随着氮肥施用量的增加逐渐下降,但两品种的氮肥回收效率、氮肥农学利用率和氮肥生理利用效率均可在N180条件下达到最高值,其中,‘济麦20’最高值分别为62.67%、5.71 kg/kg、9.11 kg/kg,‘洲元9369’的最高值分别为63.65%、7.33 kg/kg、11.55 kg/kg。综合产量水平和氮素利用相关指标,本区域强筋小麦生产中产量与氮素利用效率相协同的施氮量为180 kg/hm^2。

To clarify the optimal nitrogen fertilizer application which could simultaneously achieve high grain yield and high nitrogen use efficiency(NUE),the two winter wheat cultivars with strong gluten,’Jimai 20’and’Zhouyuan 9369’,were used as materials.Five nitrogen levels included 0,120,180,240,300 kg N/hm^2 were set.The dry matter accumulation and nitrogen content were measured through drying method and Kjeldahl method,and the relevant NUE indices were calculated subsequently.The results showed that with the increase of the nitrogen input,the yield increased first and then declined.’Jimai 20’had the highest yield at N180(7.28 t/hm^2)and N240(7.26 t/hm^2),mainly due to the balanced yield components and higher dry matter accumulation(averaged at 18.54 t/hm^2).While’Zhouyuan 9369’reached the highest yield(7.75 t/hm^2)at N180,mainly resulting from higher spikes per unit area(970.65×104/hm^2),kernels per spike(30.83 kernels/spike),dry matter accumulation(20.77 t/hm^2)and harvest index(37.33%).Although the PFPNmarkedly reduced along with the improved nitrogen level,the REN,AENand PENreached the highest value(62.67%,5.71 kg/kg,9.11 kg/kg for’Jimai 20’and 63.65%,7.33 kg/kg,11.55 kg/kg for’Zhouyuan 9369’,respectively)under the condition of N180 level.In terms of the grain yield and NUE,the suitable nitrogen level which could simultaneously achieve high grain yield and high NUE is 180 kg N/hm^2 in the region.